Tropical ostracod diversity

and paleobiogeography in the Indo-Pacific

SHIN Caren1, IWATANI Hokuto1,2, KASE Tomoki3, YASUHARA Moriaki1,2,4

1School of Biological Sciences, The University of Hong Kong, Hong Kong,2Swire Institute of Marine Sciences, The University of Hong Kong, Hong Kong,

3Department of Geology and Paleontology, National Museum of Nature and Science, Tokyo, 4Department of Earth Sciences, The University of Hong Kong, Hong Kong

Species are unevenly distributed spatially.(e.g. Tittensor et al. 2010)

Foraminifera genera diversity ‘moves’

Late Middle Eocene (42-39Ma)

(Renema 2008)

Early Miocene (23-16Ma)

Foraminifera genera diversity ‘moves’(Renema 2008)

Recent

Foraminifera genera diversity ‘moves’(Renema 2008)

Coral or East Indies Triangle,

Indo-Australian Archipelago hotspot(e.g. Briggs 2005)

Species are unevenly distributed spatially

and across time. (e.g. Renema 2008)

Ostracods (Crustacea)?

Approx. 0.2-1.0mm

Two calcite (CaCO3) valves

Est. Ordovician (485-444Ma)!

Abundant & ubiquitous

30,000+ fossil & living species

Indicators & reconstructions

This project in the Indo-Pacific

Shallow marine ostracods

150+ outcrop samples, Indonesia & Philippines

Miocene to Plio-Pleistocene (16.0-5.3 Ma and 5.3-0.01 Ma)

Results so far…

Krithe sp.

Cytheropteron uchioi

Kotoracythere inconspicua

Pistocythereis euplectellaParacytheridea hispida

Tenedocythere sp.

27 (of 44) samples

5000+ specimens

80+ unique genera

Argilloecia sp. Argilloecia cf. parallela

Genera diversity over time

Plio-PleistoceneMiocene

Genera

40

35

30

25

20

15

10

5

0

(16.0-5.3 Ma) (5.3-0.01 Ma)

Genera diversity between samples: Shannon’s H

H

Samples

Miocene

Plio-Pleistocene

0 31.5

(16.0-5.3 Ma)

(5.3-0.01 Ma)

Rarefaction

Plio-PleistoceneMiocene

0

Specimens

Taxa

100 200 300 400 5000 100 200 300 400 500

40

35

30

25

20

15

10

5

(16.0-5.3 Ma) (5.3-0.01 Ma)

Relative genera abundance in

the Miocene (16.0-5.3 Ma)

Atjehella

Neomonoceratina

NeocyprideisPistocythereis

Cytherella

14 others

(Titterton et al. 2001)

(Fauzielly et al. 2012)

(Titterton et al. 2001)

(N=4)

Relative genera abundance in

the Plio-Pleistocene (5.3-0.01 Ma)

Pistocythereis

Neocyprideis

CytheropteronArgilloecia

Krithe

80 others

(Titterton et al. 2001)

(N=23)

Pistocythereis

Neocyprideis

CytheropteronArgilloecia

Krithe

80 others

(Titterton et al. 2001)

(N=23)

(e.g. Cronin et al. 1999)

Relative genera abundance in

the Plio-Pleistocene (5.3-0.01 Ma)

nMDS of Miocene (16.0-5.3 Ma) samples

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4

Co

ord

inat

e 2

Coordinate 1 Java

Central Java

West Java

West Java

West Java

nMDS of Plio-Pleistocene (5.3-0.01 Ma) samples

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

-0.2 0 0.2 0.4 0.6 0.8 1

Co

ord

inat

e 2

Coordinate 1 Philippines Java

Central Java

West Java

Conclusions

Less diverse in the Miocene (16-5.3 Ma)

More diverse in the Plio-Pleistocene (5.3-0.01 Ma)

Unclear causes

Communities, environments, climate…?

Finer resolution species diversity needed in space & time

Thank you!Questions or comments?